Powder catapult



14, I J, FIEUX 1 2,289,766 POWDER cuAruLT Y Filed March 10, 1959 2 Sheets-Sheet 1 July 14, 1942. J FIEUX POWDER CATAPULT Filed March 10, 1939 2 Sheets-Sheet 2 VME Patented July 14, 19 2 "ou 'r ao -STATES "PATENT the device according to the invention has been OFFICE 2,289,766 POWDER CATAPULT Jean Fieux, Paris, France, assignonof one-half to Schneider 5b Ole, .Paris, France, a Jointstock company of France Application March 10, 1939, Serial No. 261,152

In France September 13, 1938 Claims. (01. 244-83) I A certain number of propulsion devices are devised for satisfactorily ensuring the braking in already'known which are applicable more parquestion. ticularly to the launching of aeroplanes, and To this end,the balanced-pressure-reducing which employ for this purpose the energy of the valve referred to above is combined with an excombustion gases of fusing products (powder or 5 hi 1 vi pera ing automatically by a differthe like) operating in a driving cylinder, the pis-' ential action ofthe internal pressures on a suitton of which they repel in the a way a a, able extension of the piston of the reducing degundrives a projectile, a; traction cable device vi the operation theta-1d p n b h f r suitably provided between the said piston and pressure reduction and for opening the exhaust the mass t be propelled serving to a pl t 10 being controlled by means of a dash-pot device the latter the effort which is to ensure the Pr vi t he end thereof. launching thereof. 1 Finally, as it is still desirable that the same The ordinary diagram of work of the' gases conat pult ho l be ap e o h un ng sidered, however, which diagram, starting from masses of very different values, for the propulsion zero passes through a and then deof which distinct, adequate fusing charges will creases up to the end of ,theexpansion zone em-- be employ e v e cc r ng to the present ployed, is such that it imposes on the different invention also comprises the ap l ati n of an members of the transmission mechanism, and i i nal rrangement whereby he aforesaid also on the masses launched and their occupants, adaptation may be immedia ly effected; constantly varying fatigues or accelerations The arr ngem n referred to compris s d in which, in order to attain the necessary launching to the first working chamber of the combustion speed for an aeroplane, for example, have to pass 811865 a certain number 0! Supplementary 01 beforehand through a value very considerably a x l ry h m s pacities which, by m -1 reater than the mean value of the force which, of a simple cock device, may at will be each put if constantly applied, would be capable of furseparately into communication with the said first laning the same work in the same time. h m er or be isolated therefrom. i

It is, therefore, of primary importance to dis: It is thus possible to adapt at will the volume cover, among the installations of the kind 'reo he aid first, chamber to the charge to be ferred to, arrangements which, due to a judicious l y this latter being itself determined in intermediate transformation of the applied effort, proportion to the mass to be launched. permit the ordinary diagram having the afore- A particular form of construction of theinvensaid accentuated maximum to be replaced by 9. tion is shown on the accompanying drawings and damped, and compensated dm m ,.wh1 h i on described hereinafter by way of example, but it the whole rendered regular and comprises an is understood of course that the said form of extended mean zone, along which the curve of as o s o m e mo fied n s c t uc I work will in practice be horizontal or substantienel details and y be o pleted by y tially horizontal, ful accessory device, without for that purpose de- According to the invention, this result is obparting f m he scope the inventiontained by subdividingthemorking chamber of In th w n referred Figure 1 s ws the combustion gases into two separate chambers 40 diametrical section of the app r r Said which are connected in series with one another, Section being made along the l n -I-I 0 Fi ure and between which there is interposed avariablewhich repr a pl n- Figures 3, 4 n action regulating pressurereducing device ensure di rammati vi ws of the typ f ee-tepult m permanently th i t a in th nd in which the carriage braking feature of the presha b r, that i t say in th ha b r in whi h cut invention is particularly adapted for embodithe launching piston moves; a substantially conment, these three figures showing th r ive p0- stant pressure having the desired mean value eitlehs. f h n hin rri pi on (a) necessary for ensuring the propulsion to be just before the catpult isflred, (b) when the carefl'ected. ,riage reaches the position in which the aeroplane As it is in addition desirable, especiallyin the le v s it, and (c) after the aeroplane has been case of high power catapults, to provide a de- 'leunehed- In o r o implify the wi of vice permitting rational, that is to say sufliciently 7 hese diagrammatic views, the powder and exprogressive, braking of the launching carriage pansion chambers and the automatic pressure after the load to be launchedhas left the latter, control means have been omitted, and t e g i e pulleys associated with the launching piston and forth, which may be opened or closed at will by means of cocks 2, I3 and so forth.

The apparatus furthermore comprises a second chamber or capacity M, in the interior of which moves the launching piston l5 to which the launching carriage 4| carrying the mass or aeroplane 42 to be propelled is connected by cables IE, IT passing over the guide pulleys l8, I9, 20,

. 2| and 43 of a suitable tackle.

In order'to pass from the first chamber 4 to the second chamber l4, the gases resulting from the combustion of the charge or cartridge 22 have to pass through the orifice 23, the pressurereducing orifice 24 and the orifice 25.

The regulating piston 26, the intermediate collar 21 of which has the same diameter as the edge 28 of the orifice 24 and as the upper collar 29 is subjected at its upper end to the pressure of a spring 30 which bears on a movable abutment plate 3| and the action of which may consequently be regulated by meanslof a hand screw 32 fixing the position of the movable plate 3|.

The said piston comprises furthermore in its lower part an extension 33 entering an orifice 34 provided in the lower end of the pressurezeducing device, the chamber 35 situated below the said orifice communicating with the exterior through any suitable exhaust pipe 36. As will be seen from Figure 1, the collar 21 and extension 33 are so positioned relatively to the orifices 24 and 34, and are of such dimensions, that the orifice 34 is not uncovered until after the collar' 21 has closed the orifice 24.

Finally, at its lower part, the said piston is extended still further to the interior ,of an oil chamber 31 forming-a dashepot due to the presence on the lower end of the piston of a disc 38, the diameter of which is slightly less than that of the chamber 3'! and whichis secured to the piston 26 by means of a nut 39.

The operation of the device is as follows:

At rest, the action of the spring 30 on the piston 26 maintains the pressure reducing orifice 24 open and the exhaust orifice closed, as

shown in Figure 1.

When the combustion of the charge 22 com-" mences, the gases, after having filled the first chamber 4 (and whichever of they auxiliary chambers 5, 6, 1, etc., may be-open), may therefore freely pass into the chamber l4; but as soon as the pressure in the latter-chamber tends to exceed the value for which the action of the spring 30 on the piston 25 has been adjusted, the pressure which is exerted on the lower face of the collar 21 tends to drive the said piston upwardly, independently'of the 'value of the pressureexisting in the chamber 4, in view of the fact that, due to the equality of the surface of the upper face of the collar 21 and the lower face of the collar 29, the piston 26 is balanced relatively to the said pressure in chamber 4.

Finally, the collar 21 tends toclose completely the orifice 24.

At the same time, however, the pressure exerted in the chamber M on the working piston with the chamber 4 by passages 8, 9, l0 and so l I 5 tends to drive the latter outwardly, thereby commencing to propel the launching carriage 4| to the right away from its at rest position as shown in Figure 3.

This movement of the piston l5 causes the pressure in the chamber l4 to drop immediately, and under the action of the spring 30, which becomes preponderant, the piston 26 re-descends and the orifice 24 is re-opened, the combustion gases which are at a higher pressure in the first chamber 4 than the pressure considered again flow into the second chamber l4 and the movementbontinues, any oscillations which may be produced being attenuated by the dashpot '31.

When the piston l5 has arrived at the end of its outward stroke, that is to say at,t he momentwhen the launching carriage 4| is abreast of the guide pulleys 43 and the mass to be launched leaves the launching carriage (see Figure4), the latter, continuing its course under the action of the momentum which it has stored up, tends to cause the piston I5 to enter the cylinder 40 as indicated in Figure 5.

In order to prevent the gases filling the said cylinder from opposing an excessive resistance to .the inward movement of the piston and consequentlyimposing on the launching carriage an excessively sudden stop which might be harmful both for the traction cables and for the whole of the mechanism, it is necessary to allow these gases to escape.

This result is obtained due to the fact that under the action of the increase in pressure which is produced in the chamber I4 and which acts on the lower face of the collar 21, the piston 26, despite the antagonistic action of the spring 30, re-ascends sui'ficiently to uncover the orifice 34 and consequently to permit the gases contained in the chamber H to escape through the discharge pipe 36.

There is thus provided an extremely flexible a pressure chamber into which the gas is deliv-' ered upon production, a second chamber connected in series with said pressure chamber, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, and means responsive to the pressure 01 the gas in said second chamber for automatically controlling the flow of gas between said chambers, whereby the pressure in said second chamber producing the propelling movement of said piston may be maintained substantially constant. I

2. In a catapult of the character described wherein the energy of gas produced by combustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered upon production, a second chamber connected with said pressure chamber through a pressure reducing orifice, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, and means responsive to the pressure of the gas in said second chamber for automatically controlling the fiow'of gas through said pressure reducing orifice, whereby the pressure in said second cham- 2,289,766 ber producing the propelling movement of said' piston may be maintained substantially constant.

3. In a catapult of the character described wherein the energy of gas produced by combustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered upon production, a second chamber connected with said pressure chamber through a pressure V reducing orifice, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, and means responsive to the pressure of the gas in said second chamber for automatically controlling the fiow of gas through said pressure reducing orifice, said means comprising a control piston balanced with respect to the. pressure in said pressure chamber and having a portion adapted to control the fiow of gas through said pressure reducing orifice, yieldable means exerting a biasing force against said control piston tending to maintain the latter in a position such that the fiow through said orifice is at a maximum, and means subject to the pressure of the gas in said second chamber for moving said control piston toward orifice closing position'in opposition to the biasing force of said yieldable means. l

4. In a catapult of the character described wherein the energy of gas produced by combustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered upon production, a second'chamber connected with said pressure chamber through a pressure reducing orifice, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, and means responsive to the pressure of the gas in said second chamber for automatically controlling the fiow of gas through said pressure reducing orifice, said means comprising a control piston balanced with respect to the pressure in said pressure chamber and having a portion adapted to control the fiow of gas through said pressure reducing orifice, and a spring tending to maintain said control piston in a position such that the flow through'said orifice is at a maximum, said control piston also having a portion subject to the pressure of the gas in said second chamber and so arranged that said latter pressure opposes said spring and tends to move said control piston towards orifice closing position.

5. In a catapult of the character described wherein the energy of gas produced by combustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered upon production, a second chamber connected with said pressure chamber through a pressure reducing orifice, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, and means responsive to the pressure of the gas in said second chamber'for automatically controlling the flow of gasthrough said pressure reducing orifice, said means comprising a control piston balanced with respect to the pressure in said pressure chamber and having a portion adapted to control thefiow of gas through said pressure reducing orifice, a spring tending to maintain said control piston in a position such that the fiow through said orifice is at a maximum, means .for adjusting the pressure exerted by said spring on said control piston, said control piston also having a portion subjecttdthe pressure of the gas in said second chamber and so arranged that said latter pressure opposes said spring and tends to movesaid control piston toward orifice closing position, and means for damping the oscillations of said control piston due to the variations in pressure in said second chamber.

6. In a catapult of the character described wherein the energy of gas produced by combustion of a charge of powder, is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered upon production, a second chamber containing a launching piston movable therein and operatively connected with the mass to be propelled, a cylinder communicating with both of said chambers, a control piston movable in said cylinder and controlling the fiow of gas from said pressure chamber to said second chamber,

yieldable means continually urging said control piston toward a position such that said fiow of gas is at a maximum, and means responsive to the pressure or the gas in said second chamber for moving said control piston in a direction such as to restrict said flow.

- wherein the energy of gas produced by combus- 'ment of said piston tion of a charge of powder is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered: upon production, a second chamber connected with said pressure chamber, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, means responsive to variations in the pressure of the gas in said second chamber for automatically controlling the fiow of gas between said chambers, whereby the pressure in said second chamber producing the propelling movemay be maintained substantially constant, a normally closed outlet for exhausting the gas from said second chamber, and means associated with said first named means for opening said exhaust outlet when the pressure in said second chamber exceeds a predetermined value.

8. In a catapult of, the character described wherein the energy of gas-produced by combustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a pressure chamber into which the gas is delivered upon production, a second chamber connected with said pressure chamber through a pressure reducing orifice, a launching piston movable in said second chamber and operatively connected with the mass to be propelled, "and means responsive to the pressure of the gas in said second chamber for automatically controlling the fiow of gas through said pressure reducing orifice, said means comprising a control piston balanced 'with respect to the pressure in said pressure chamber and having a portion adapted to control; the fiow of gas through said pressure reducing orifice, yieldable means exerting a biasing force againstv said control piston tending to maintain the latter in a position such thatthe fiow through said orifice is at a maximum, means subject to the pressure of the gas in said second chamber for moving said control piston toward orifice closing position in opposition to the biasing force of said yieldable '7. In a catapult of the character described same when the pressure in said second chamber exceeds a predetermined value.

, 9. In a catapult of the character described wherein the energy of gas produced bycombustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a 1 pressure chamber into which the gas is delivered upon production, a second chamber containing a.

launching piston movable therein and operatively connected with the mass to be propelled,

a cylinder communicating with both of said' chambers, a control piston movable in said cylinder and controlling the flow of gas from said pressure chamber to said second chamber, yieldable means continually urging said control pisher, and means movable with said control piston normally closing said outlet, said last named means acting to open said outlet when the presmay be varied at will.

2,289,766 sure in said second chamber exceeds a predetermined value.

10.In a catapult oi the character described wherein the energy of gas produced by combustion of a charge of powder is utilized for moving the mass to be propelled, the combination of a main pressure chamber into which the gas is delivered upon production, a second chamber connected with said pressure chamber and containing a launching piston movable therein and operatively connected with the mass to be propelled, means responsive to the pressure of the gas in said second chamber for automatically controlling the flow of gas between said chambers, a plurality of auxiliary pressure chambers associated with said main pressure chamber, and valve means for individually establishing and disestablishing communication between said auxiliary chambers and said main chamber, whereby the effective volume of the pressure chamber into which the gas is initially delivered JEAN FmUx. 

